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 Signature Internal Medicine

Concierge Internal Medicine located in Frisco, TX

Dr. Ahmed and Dr. Diehl
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What is concierge medicine?

Signature Internal Medicine is a superior concierge internal medicine practice in Frisco, Texas, led by Humera Ahmed, MD, and Dina Diehl, DO. The skilled providers offer comprehensive primary care services for men and women 18 and older.

Signature Internal Medicine offers 24/7 access to physicians any time patients need them. Providers spend as much time as patients desire to ensure exceptional care, so appointments never feel rushed.


  • 24/7 access to your physician by phone, email, text
  • 30-60+ minute appointment times 
  • Little or no office wait times
  • Complimentary health coaching
  • Comfortable, relaxing environment
  • Comfortable, friendly environment
  • Improved disease management
  • Early disease detection with advanced testing options
  • Cutting-edge diagnostics and treatments offered
  • Same-day or next-day appointment availability
  • Personalized attention to your needs
  • Specialist referrals in timely fashion 
  • Coordination of follow-up care
  • White glove service

Annual membership fee : individual $3000/year, couples $5000/year.  This fee can be paid annually, biannually or quarterly. This fee is not covered by insurance. Our annual membership covers these practice benefits. We accept most insurances for medical visits, labs, and diagnostic testing if applicable. You may request a complimentary meeting with one of our providers to see if they are right for you.

Well-trained, experienced physicians at Signature Internal Medicine specialize in preventive health care. The offer executive level annual physicals with option for extensive lab testing, imaging in addition to comprehensive internal medicine services, and more.
Optional add on labs:
  • Advanced Cleveland Heart Labs
  • Extensive Thyroid panel
  • Hormone analysis (i.e Dutch testing) 
  • Gut microbiome analysis ( GI MAP test)
  • Food Sensitivity Testing 
  • Adrenal/Cortisol Analysis 
  • Detailed Vitamin Analysis 
  • Metabolism/Amino Acid Testing 
  • Neurotransmitter Testing
  • Toxin Evaluation 
  • Oxidative Stress Analysis 

The practice provides exceptional concierge medicine, which is a newer approach to healthcare in which your primary care physician limits the size of the practice. This allows them to spend more time with patients and deliver the personalized attention they deserve.

Along with 24/7 access to your provider, concierge medicine provides same-day or next-day appointments with little to no office wait times. Your Signature Internal Medicine provider focuses on patients’ unique needs, tailoring treatment plans just for them.

The highly-trained providers care for patients with diabetes, chronic obstructive pulmonary disease (COPD), high cholesterol, hypertension, osteoporosis, gastrointestinal reflux disease (GERD), and mental health conditions. 

Signature Internal Medicine offers medical weight loss, chronic disease, and acute illness management, prescription medicines, cancer screening, smoking cessation, on-site diagnostic testing, and much more. The internal medicine providers work and communicate closely with specialists, referring patients to them when necessary.

The Signature Internal Medicine specialists warmly welcome their patients to the practice and look forward to caring for them. 

Call the office or use the online booking tool today to schedule an appointment at Signature Internal Medicine.

Meet Our Providers

Dr. Diehl and Dr. Ahmed currently have privileges at Texas Health Hospital Plano & Texas Health Hospital Frisco
Dr. Diehl Memberships/Awards
Dr. Diehl

- Board Certified in Internal Medicine - Board Certified in Obesity Medicine - Certified Functional Medicine Provider - American College of Physicians
- Certified Functional Medicine Provider
- Member of Institute of Functional Medicine
- Member of American Medical Association
- National Committee for Quality Assurance Excellence in Diabetes Care 2017
- Board member at Texas Health Presbyterian, 2010 
- Certificate of Recognition for Delivery of Quality Cardiovascular and Stroke Care 2017-2020

- America's Most Honored Professionals 2019 - Top 5%
- America's Most Honored Professionals 2018 - Top 1%
- America's Most Honored Professionals 2017 - Top 5%
- Compassionate Doctor 2015
- Compassionate Doctor 2016
- On-Time Physician Award - 2016
- On-Time Physician Award - 2015
- Patients' Choice 2016
- Patients' Choice 2018

Dr. Ahmed Memberships/Awards
Dr. Ahmed

- Board Certified Internal Medicine - Board Certified in Obesity
- Member of Institute of Functional Medicine
- D-Magazine Best Internist in 2018, 2019 and 2023 
- National Committee for Quality Assurance Excellence in Diabetes Care, 2017
- Recognized for Delivery of Quality Cardiovascular and Stroke Care, 2017-2020
- Board member at Texas Health Presbyterian, 2010
- Member of the American College of Physicians
- Top doctors of America selected in 2022
- America's Most Honored Doctors - Top 5% 2022
- America's Most Honored Doctors - Top 5% 2021
- America's Most Honored Doctors 2020 - Top 5%
- Compassionate Doctor 2020
- On-Time Physician Award - 2020
- Patients' Choice 2020
- Patients' Choice 2019
- Biote Certified

Patient Reviews


Lanette H. | Dec 20, 2023
Great communication. Very good call.

Joseph D. | Nov 30, 2023
Best doctor ever

Raymond M. | Oct 25, 2023
She listens & discusses your current sickness. Then suggests things for you to do to help get better & she explains what medicines she is prescribing and how they should help. Then in a couple days she calls you to see how you are doing & makes further suggestions.

Lila A. | Aug 16, 2023
Quick, detailed, and comprehensive appointment with her!

Umar A. | Jul 24, 2023
It was great

Spencer P. | Jul 15, 2023
Dr. Ahmed is very caring physician.

Artel K. | May 26, 2023
As a an executive with a busy schedule, working with Dr. Diehl as a patient can only be described as : Focused, Precise, Reassuring, and Confident. I appreciate the flexibility and support Dr Diehl and the entire Signature team provides. I always walk away feeling better. Cheers !

Gregory M. | May 01, 2023
Very, very thorough during your office visit. Really listens and takes the time needed when you are with her which is so refreshing and makes me confident I am getting the best care.

Carmen W. | Apr 27, 2023


We accept most insurance providers. If you have specific questions regarding your coverage, please contact us for additional information.

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